| Native Name: | 難兄難弟之神探李奇 |
| Alt Name: | Old Time Buddy 2 |
| Genre: | Period drama Romantic comedy Mystery |
| Director: | Chan Wai-koon So Man-chung Wong Ciu-ying Mak Koon-chi Wong kwok-koon Man Wai-hung Chung Shu-kai |
| Starring: | Gallen Lo Gordon Lam Maggie Cheung Elaine Ng |
| Opentheme: | Se Ma Ru by Gallen Lo and Maggie Cheung |
| Theme Music Composer: | Shunsuke Kikuchi |
| Country: | Hong Kong |
| Language: | Cantonese |
| Num Episodes: | 25 |
| Executive Producer: | Tommy Leung |
| Producer: | Chung Shu-kai |
| Editor: | Bau Wai-chung Chow Yuk-ming |
| Location: | Hong Kong |
| Camera: | Multi camera |
| Runtime: | 45 minutes |
| Company: | TVB |
| Network: | TVB Jade |
| Related: | Old Time Buddy |
| C: | 難兄難弟之神探李奇 |
| L: | "Difficult Older Brother, Difficult Younger Brother-Detective Lee Kei" |
| J: | naan4 hing1 naan4 dai6 zi1 san1 taam1 lei5 kei4 |
| P: | nàn xiōng nàn dì zhī shén tàn lǐ qí |
Old Time Buddy: To Catch a Thief (; literally "Difficult Older Brother, Difficult Younger Brother-Detective Lee Kei") is a 1998 Hong Kong period romantic comedy television drama created and produced by TVB, starring Gallen Lo, Gordon Lam, Maggie Cheung, Elaine Ng as the main cast.[1] The series is an indirect sequel to 1997's Old Time Buddy. Filming took place in early 1998 entirely on location in Hong Kong. Original broadcast began on Hong Kong's TVB Jade channel August 3 till September 4, 1998 every Monday through Friday during its 7:30 to 8:30 pm timeslot with a total of 25 episodes.
Although it is the second installment of the Old Time Buddy series the story and characters have no connections to the first series. While the first series focuses on Hong Kong film industry in the 1960s, the second series is adapted from plots of 1960s Hong Kong detective mystery films such as The Black Rose (1965) starring the real life Connie Chan.
Lee Kei is a righteous cop in Hong Kong during the 1960s, a rarity among his peers. He goes undercover to find the infamous cat-burglar "Black Rose", who has escaped capture for over twenty years. His first clue leads him to a nightclub, where he is reunited with Tse Sei, a slick talent manager and Kei's former classmate. Sei is in some trouble for not having paid the triad's talent their fee so Kei allows him to stay with him.
Later, Kei's corrupt supervisor discovers Kei's undercover operation. He gives Kei one month to find the "Black Rose" or he will fire him. When Kei returns home, he finds it burnt down by the triads, who were looking for Sei. Having caused all this trouble, Sei lets Kei live at his uncle's home. Sei's uncle works at an amusement park and live together with all the employees in the same apartment. The other tenants include brassy girl Siu Fong-fong, who tends the coin toss game booth at the park, and martial artists Cheng Po-chu and her mother. At the amusement park, Kei finds similarities between Cheng's acts and the martial arts used by the "Black Rose". He suspects that Cheng's mother is the "Black Rose" and decides to keep a close eye on the duo.